Venmo is instantly reverisble much like credit debit. This is one of the most DANGEROUS ways to sell bitcoins and is favoured by scammers. We discourage using Venmo unless it is for very trusted trade partners.
Venmo reversed funds, and cited it was due to the seller's venmo only having one successful trade. They also accused RevBTC of using stolen cards. I am awaiting a refund. If I get refunded the BTC this feedback will change to positive, but for now I am being advised to mark it as negative.