Billing problem

We went to Angola in April/May 2015 for holiday, my bank acc was debited end of May R65822.17. On the 30/5/2015 i emailed mtn cust care for my statement to see what is going on. They rep**** with security check, i completed and sent back. Thereafter i heard nothing and sent another 6 mails to them, requesting my itemised billing to try sort out the problem. They sent me the link on 8/6/2015 but only statement was showing that it was roaming calls and not itemised billing as requested. Thereafter i sent 15 mails again to mtn still requesting my itemised billing, i phoned numerous times also requesting it, and never got it on cell number in question, when i phoned they kept telling me it roaming calls,i wnt to the branch in Groblersdal and Witbank they also told me its roaming calls. Eventually 19/10/2015 Glenda assisted by sending itemised billing as requested for 5months. When i went it through it showed on 8/5/2015 an amout of R54256 for internet use which Glenda confirmed 19/10/2015. HOW THE HELL CAN IT BE ROAMING CALLS APPARENTLY ALL THE TIME, BUT NOW ITS INTERNET. I HAVE PHOTOS OF MY HOLIDAY DAY,TIME!! All 3 my accounts have been cut, can anyone assist, cause MTN is incapable