They made it very difficult to reach a human being, but yes, they do have a call center.

I've been following this protest for a bit out of curiosity (because I really do think Visa/Mastercard is problematic).

But almost all the Reddit posts or Tweets I've seen are about Visa call centers or Mastercard call centers. The number of people protesting Stripe is miniscule in comparison (if there even is anyone to begin with).