What is a refund of 200% or 300%?

This is the rate of reimbursement based on the scales of social security.
Some doctors may charge higher fees ...

for reimbursement at 200%: 2 x 22 € - 14.4 € (amount taken up by social security)
for reimbursement at 300%: 3 x 22 € - 14.4 €