Vodacom inconveniencing me on communication as swapping my cellphone.

Around June 18, Vodacom swap my contacts in reference to communication. For example, Cellphone 1 is getting SMSs or calls as if its Cellphone 2. This is creating a problem and inconveniencing me as recently I cant upgrade my contract as they are calling a different cellphone. Please sort out the communication on my numbers i.e. cellphone 1 should get SMSs/Calls intended for cellphone 1 not what is currently happening.