cisco vpn with Tmoble home internet

I got T-Mobile home internet 9 months ago. It's been great, no issues whatsoever. Jan 10 all of a sudden if I had the VPN on I couldn't get into my other company apps, internet etc. After alot of back and forth with my IT dept. & no fix, on Jan 23 I called T-Mobile who said they absolutely do not have a problem like this and have made no changes, it has to be my company. 

I tried using a hot spot and it would work for a bit then cut out. It would work off and onwith no consistency. Cut to this week still having issues and no resolves. IT says they've never seen this, but a different person git involved, said he's sure it's the ISP firewall or something causing the issues. I called T-Mobile last week, and oh by the way, we started having poeple call in with a problem with Cisco VPN. Huge disappointment with T-Mobile. They sent me a new gateway and so far 1st day everything works. Not to happy that I belive I was not told the truth in January and someone should have been more willing to look further into the issue instead of being so sure its not their problem. Wish I'd been aware of this forum sooner and I hope others see it.