Tikona Broadband - Internet service not installed on time

I made payment for Tikona internet service on March *, ****. The sales person said me they will immediately install the internet service after payment. Their engineer came and said there is a need for P*P connection and another engineer will arrive in * days. However no one came. So many times I called their sales agent and customer services. They kept saying we will look into in but nobody did. I needed it urgently for my exams which I kept saying them. Later on after few weeks lockdown was announced and now they have this good reason to get away with this. They are not even replying back about the status of installation or refund. I lost two months of my studies because of these people and I have my exams in Sept. Who will bear the cost if I failed it? Mental torture of calling customer care, sales person, senior of them is to another level.