Very bad network signal

I have ported my number from MTN to Telkom. With shock to see that I do not have network coverage at home. I went back to Telkom to ask if I could please Port out from Telkom back to MTN. They refused and said I must be on their network for 90 days. I understand the reason for this but I need a functional phone as I’m trying to find work. I request humbly that Telkom release my number to port back to MTN. It is not my fault that Telkom cannot supply a functional stable network