T mobile Scam for my international Plan

Hi, I have been using T mobile International call plan (USA, Canada and Mexico) since last 6 . The plan provides for free text and calls from canada to usa, within usa and Mexico.Eventually, the plan doesn't work until I refill my prepaid account with $10.I have done almost 100 of reharges of $10 as I was never provided a resolution. Every time I call them they tell me The text message was sent from UK and they also provide me number.Then I do 2 things:

1. Check for the number and the contact was my realtor who has not been out of USA since last 10 years
2. They allegedly tell me i might have travelled to Uk which i have never in last 10 years
3. They then make up stories your realtor might have travelled to UK and sent you text and then you got charged (Making up all the stories)

what should I do now ? How can i get refunded at-least and made some compensation.I have been ripped off so many times now