Bitcoin is a Snitchcoin. Everything is does everywhere it goes and everyone trading in its entire history is tracked and publicated %100 all the way down to the IP address.
Closest thing you can get away with that is to swap Monero for the Bitcoin on Bisq.
Monero is anonymous. %100. Regular upgrade to the shuffling of the anonymity is by design and happens between twice a year and every other year.
Mullvad accept Monero directly. No third party snitch tracker doing the acceptance for them. They give the same discount for the payment method.