Lack of service delivery

I placed and paid for an online order for Ncr books on the 7th of June 2022. Delivery was set for the 22nd of the same month. Today it's the 27th of July I still haven't received my books. Towards the end of June I contacted them and they told me they had a backlog in production due to loadshedding and they requested a further 7 working days. They have been quiet ever since. Today I tried calling and their calls are not going trough. The only communication available is the online chat which hasn't been helpful thus far. No update no apology just complete silence.