I want my phone back

I bought a phone on the 25th of may 2020,two months later the charging pin was not working properly and I returned the phone on the 10th of August 2020 for repairs,when I got to Ackerman's I asked how long should I wait to get it back they said 21 working days , after 21 days I called to ask if my phone is back yet but to my surprise the phone was still in the storage of the store,its been more than 30 days and I still don't have my phone with me.been going to the store but it seems like they don't care .