PREPAID TO CONTRACT MESS!

Good day, last week i added a 3rd contract to my existing account (for my dad). Since last week Thursday this phone number is unable to make any calls (after the sms that says it is now on that contract package), i have phoned about 8-10 times regarding this issue. I have done a sim swop aswell to a new simcard and nothing is wrong with the phone, all outgoing calls says call ended, and when it goes through it says the number you have dialed is incorrect, even if you phone 808 when it does go through it says the number is incorrect, it is able to receive incoming calls and smses, it can also check airtime and send smses, services affected is making calls and internet usage attempts shows NETWORK ERROR. Please sort this out as my dad is on the road having no way of contacting anyone, the number giving thos problem for almost a week is *** please fix it urgently , please contact me on ***.