Check this page out if you want to see the real speed instead of the port speed if it connects:
http://www.modemsite.com/56k/x2-inf1.asp
But I don't get how you can suddenly get 115200 bps instead of 33000 or such, because it's a fault on their end and getting the port speed instead of the connect speed is something that is configured in your modem. It was probably some firmware problem, maybe no good V.90 (speeds above 33k6) interoperability between their modem(s) and yours, so you got V.34 connections (33k6 and under, so only analogue data, because speeds above 33k6 MUST have a digital V.90/V.92 carrier). If you get the normal connect speeds working, could you post your actual connect speed here?
Oh, little sidenote: The connect speed could give something completely different than your speed is. If it connects at 50666 bps for example, it could've have tested the line wrongly when connecting, so your modem retrains (sort of reconnecting to redetermine the maximum speed). Check out the following page to determine your real throughput:
http://www.modemsite.com/56k/x2-thru.asp