Roaming rip-off

Whilst roaming in the UK for 18 days I used WhatsApp only, and Mail (but only when connected to WiFi). With the exception of WhatsApp all Apps were switched off unless I was connected to WiFi. I received a bill in excess of R7000. I disputed the bill at MTNSP Morningside. In trying to resolve the matter I visited the store 4 times and visited MTN 14th Ave head office once. I wrote numerous emails and made a number of telephone calls. MTN were unable to explain how the roaming charges had been determined. They failed to deliver on promises made. Due to my persistence I did receive reports which failed to explain the charges. Ultimately I was offered 33% off my bill, but this still left me with an invoice way in excess of the amount I expected to pay. Having analysed the reports my opinion is that MTN are being ********** by ORANGE PCS, a UK service provider - but MTN is not prepared to confront the issue on behalf of its clients. Bad service and ********* - I'm leaving!