Worst customer service ever.

About 4 months ago vodacom called me and offered a better deal on my line,this person promised me i will be paying R100 less on my subsription but when my bill came a month later it was in fact almost R700 more. I called in as soon as i got this invoice and requested that i be migrated back to my original package as i can not afford that and i did explain this to the consultant.the consultant that assisted me promised that they would put in a credit request, i was stupid to believe this as a month later my line was blocked and no credit was done..since then i have called in more than 5 times regarding this matter.i have neen blocked every month since then and this is getting rediculous..i have a reference nr for this credit to be done..what is so difficult ?. The credit note shows on their system as in progress for approval but again this morning my line is blocked and now they are not open for bussiness hours and i cant call out,i pay my normal bill every month on time but because of this migration i am in a arrears with the money they added to my bill and they have gone and listened to this recordings proving that i did tell this person that i do not want to oay more thst what i was paying and still they promised it will be R100 less on my bill and this is so so so un fair..if i knew this was the service i was going to get by vodacom i would have never signed a new contract..this is the worst service ever..why do i get punished for Vodacom not being able to do their job on a timely manner?????