what is RMCS

I have an account with jet and always buy my airtime using my account, recently I purchased three recharge vouchers that I never received, I have sent more than one complaint to edcon for the past two weeks, their feedback was that, they have sent my query to the relevant department, today I've sent an email using capital letters, guess what? they now say I should contact a company called rmcs which I don't know and all along I thought I buying my airtime from Jet, I am so disappointed with them 'cause I have been sending my compliant to them without any solution or telling me the truth of what is going, they told me this because I told them I'm going to cancel my account. How is it that they allow a third party to have access to our account but when we need help they are unable to assist.