u/Happy-Manufacturer11

I was a new LLC owner and started paying quarterly taxes once I new I had to. However, I made payments as balance due instead of estimated payment for the year. Now the CPA has me pay underpayment penalty and interest for it and refuses to make any request to IRS but wait for the balance pay money to be refunded. It's become impossible to speak to someone at IRS to request anything. What options are available to deal with this situation ? We did have disaster relief granting tax filling extension to June 8th, and I think there is a way to request waiver of underpayment penalty etc but do not have much info on that. Would appreciate any useful information