Unhappy customer

Please assist me as I am very ****ed off with Pep store, I bought my Hisense E 30 lite at Pep store in South Gate Mall. It had problem with the screen I returned it on 20/04/2021 and I bought it on the 21/02/2021. Promising to callback after 3 weeks up until now no call from them.I went on 23/05/2021 to check for any progress and I didn't get they said it's still at repairs. It's been 2 months now and I feel very inconvenienced because that's my only phone how am I suppose to do my homework as some ofthem needs me to goggle