I’ve completely paid off in advance the EIP on 2 phones, and this caused 1 month’s worth of their EIPs to get double-charged to my current bill. There are similar community discussions, but either the OPs didn’t specify whether they’re making a partial or full payment or the answers seem to apply only to cases of partial payment.
Here’s an example of partial payment. Assume Client’s bill occurs at the beginning of every month and is $100, which includes $15 monthly EIP. It’s Jan. 20 and he has $60 EIP balance remaining (4 months’ worth), so if he pays bills normally ($100/mo.) from Feb. 1st to May 1st (inclusive), his EIP balance becomes zero, and his bills from June 1st and on should be $85/mo.
Instead, he decides to make an advanced partial EIP payment of $30 on Jan. 20th, or two months’ worth. He expects to be billed $100/mo. on Feb. 1st and March 1st and $85/mo. from Apr. 1st and onwards, because he’s brought forward his EIP zero-balance date by two months.
But what actually happens is his Feb. 1st bill becomes $100 - $30 = $70. He’s temporarily saved $30. But because it went to the device’s total EIP balance and not February’s balance (not even February’s slice of the total EIP balance), that $30 temporary savings gets debited to March’s bill, making it $100 + $30 = $130. In March, the client is paying for two months’ EIPs—February’s $15 (which is included in that $30 debit) and March’s own $15—and whatever other fees left of February’s from that $30 debit, all this in addition to the rest of March’s service fee. The mid-January advanced partial EIP payment effectively belongs to no one month’s bill, but after March’s bill, 4 EIP payments’ worth have been made: 2 in the advanced payment, 0 in February’s adjusted bill, and 2 in March’s adjusted bill. The total EIP is paid off by the end of March 1st, and because April’s bill is $85 as expected, the EIP zero balance date was indeed brought forward to the expected date. Because the sum of February and March’s bills is $200 in the scenario the client expected ($100 Feb. bill + $100 Mar. bill) and $200 in the scenario that actually happened ($70 Feb. bill + $130 Mar. bill), this artificial inflation of March’s bill results in no overcharge when summing February’s and March’s bills.
An overcharge happens if this client instead makes an advanced “full” EIP payment on Jan. 20th. Because he expects the EIP to be completely paid off, he expects every bill from Feb. 1st and onwards to be $85 each. He pays the full EIP balance of $60 on Jan. 20th. What actually happens is his Feb. 1st bill becomes $100 - $60 = $40. The temporary $60 savings is debited to March’s bill. March’s bill is $85 (because there is no more EIP balance and therefore no more $15/mo. EIP charge) plus the $60 temporary savings from February's bill that was debited to March's bill: $85 + $60 = $145. Summing February’s $40 bill and March’s $145 bill yields $185. But the sum the client expected is $85 (Feb.) + $85 (Mar.) = $170. Client ends up overpaying $15, or 1 month’s EIP. The problem is the system blindly added to March’s bill that $60 temporary savings of February’s bill which includes a redundant EIP portion, the last of which was already paid off on Jan. 20th. This problem cannot be resolved by bringing forward the EIP zero-balance date by one month because there is nothing to bring forward—the EIP balance had already been zeroed on Jan 20th. The problem scales up with the total price and quantity of devices.
I’ve spent 2 hours on live chat but the rep was dismissive and was asking where I got certain numbers relevant to my bill that I’ve and he’s provided moments prior. The itemization on my bill is also erroneous, because these double charges were distributed across the already paid off devices’ EIP items. They weren’t consolidated into an item that remotely indicates an adjustment/debit from the prior month. I want the double-charged amount of one month’s worth of EIP on the two devices I’ve paid off in advance credited back. I wouldn’t have paid to get on the hook to pay more.