MTN poor customer service.

3 days ago i went to mtn store in promenade to apply for contract. the sales lady who helped me said i approve only for 299 a month. i said i would like to have a p20 lite then she said out of stock. secondly she requested for a R49 extra on a monthly payment for me for the sony xa2 ultra. the following day i came in to mtn store and still it was processing. i told her to cancel and do the 299 contract and so we proceeded. she told me to come back in 20 minuites and when i did she said its still processing. then she send me back home and said come in anither 1 hour. i did so , but when i arrived she were gone and i have to wait in a long que again. Again i was helped and still it was processing. i was supposed to have a phone today for work , as i could have bought one ,but i was promised to have it yesterday. i feel mtn is very disappointing and unprofessional in customer service. what should i do now .