My wife had a business addon to my phone which gave her a cheap plan, but recently we moved her to one of the standalone plans with VF. It wasn't seamless, and since then her mobile data won't connect above H+ speeds 

She called VF who wanted her to put the sim into another phone (she doesn't have one) and then after much mucking around, it was escalated, and crickets since. 

Is there anything I can do on the phone (Should it be using a different APN or whatever) to get her back at reasonable speeds or am I stuck waiting till VF sort it at their end?