Chargeback Fees and Refunds

[JuegosMC]

Hi, I am fairly new to PayPal, using the money system to process payments from websites. I am wondering if someone chargebacks on my server, obviously the funds will automatically be withdrawn from my PayPal account, now this is the part which I am concerned about. 

I have a Minecraft server which is open for donations to keep up the server and maintaining it, I got confirmation that I don't get seller protection. What I am concerned about is that I have to pay a processing fee of $20 per successful claim or chargeback, when someone issues a chargeback do I HAVE to pay that, can't I just refund the buyer? 

I am slightly concerned about this, because I have no way of paying for hundreds of fees etc. Please can someone help?

Also, I refunded some people. Are they still able to chargeback and I still pay chargeback fees? Kinda worried as of now.

[Userncc1701]

Chargebacks are dependant on the credit card company. Although most will be met if they meet the criteria there may be circumstances when they are not. As I understand chargebacks, if a PP dispute has been found in your favour and you suffer a chargeback, PP waives the fee. The inference being if there is no dispute or not found in your favour, you will have a chargeback fee applied to your PP account.