It will have a negative effect on your report. 2 new accounts will bring your AAoA down more than 1 new account. If you only agreed to open 1 account and they opened 2 without agreement, then you can dispute that. A new account is not the same as a new card. I was dispute it as much as possible.
What other accounts do you have?
Depending on what plan you're going with regarding a refinance, the difference between 720 and 760 is likely irrelevant anyway and won't affect your offered rate at all in that case. I don't think you have a lot of options in this case, and frankly you're gold plated anyway especially if that Beacon 5.0 score of 755 is w/Care Credit balance reporting and that swings your utilization rate by some non-trivial amount.
I absolutely would not dispute it though (or continue to do so in this case); having any tradeline in dispute can be problematic in all sorts of ways when it comes to loan origination.