SKY HIGH bill after asking for a limit to be set

on the 08/07/2015 I was chatting on vodacom online and a lady called me back where i was raising my concern for a r300 bill after I asked for a limit to be put on as this tablet with the high bill of R3200 belongs to my 9 year old son. I was given a ref number and migration forms and was promised that the limit is set of R50.00 after a week the bill was R3200 and i logged another ref with Tsepiso from accounst who promised womeone will get back to me and than Zama who was really trying to asssit and gave a ref A1-X8DC-EVE2WO and up untill today no info just bills from collections.WHAT IS HAPPENING IS MY CALLS NOT RECORDED???Can A PERSON PLS EXPLAIN WHY THE Limit was not implemented in the 1st place and why so many people are not getting this right.