double charged for data and limits removed

I was a nashua mobile customer and could buy data using *141*2# and account would lock when limit was reached and i was transferred to mtn sp. In November and then problems started . Account limits was removed from all 3 contracts and was rest after getting large bill In January that i payed . As i thought it was due to limits removed. After getting large bills in April and May i spoke to call centre twice and got nowhere. I went to main customer centre in bfn and found mtn was striking and the clerk that helped me said she wil log a report would let me know but may take long becouse of strike. And i was informed that i can not buy data using *141*2# menu . But money was deducted for bundle every month and al data was charged at out of bundle rate even if it showed the bundel balance if i checked at *141# and gave me notifications when it was used up or expired.