How we can give to satisfaction to our existing customer while our competitors are giving better service on the same charges?

You need to look back again your Product & Services part which you had decided to cater to your customer.  Because if your product was Price sensitive you need to compromise with only price because your customer were Price conscious but if your product or services were based on other sensitive factors then you need to changes your strategy again. Not every customer can be retained or acquired on the basis of Price and better price does not guarantee of better or best services.