Stole airtime from me

I have been with you for 13 years and this is how you treat a loyal customer, who has also never defaulted on payment. I have a topup package and loaded R60 airtime on it on Saturday. On Sunday I did a contract upgrade (to another topup package) and found out today that I have lost the R60 airtime. This is the biggest load of ******* I have ever heard and I was NOT informed of this either! In fact, I have never heard of this. Every time I have upgraded my airtime/sms/data has been carried through. I will NOT accept losing R60! I want my airtime back or my account credited with R60.