I filed my 2020 taxes (extension) in October2020 . It has been 7 months and I still haven't received my federal refund. The IRS web site say its taking longer than usual

did you check your transcript at IRS.GOV? does it show a payment to you? 

is it possible they sent it and it got lost? 

were you expecting direct deposit or a paper check? 

(and I'll assume you read the letter correctly and it shows a refund and not money owed????)

direct deposit 

I can't find the original letter however I logged into my IRS account and it says a refund was issued but we haven't received it. 

I'm sure I read the letter correctly.

If the IRS transcript shows it was sent out then check your bank records carefully.   If it was never received you have to put a trace on the missing payment :  

To start a payment trace:

• Call the IRS at 1-800-919-9835
• Mail or fax a completed Form 3911, Taxpayer Statement Regarding Refund