getting ripped off x 4 on ebay and new checking account policy means they are charging me for it

[pilgrim_salem]

i have sold 4 gift cards in last month. Really none ended up as legit as supposedly 4 different transactions resulted in my receiving an ebay email: MC010 Account Security Communication Partner Warning that "this account was recently found to have been accessed by an unauthorized third party, who may have used the account in an attempt to defraud other members."

First the RIPOFF that ebay has done since converting to sending & passing to my check account. For each transaction they took back the monies that the supposed buyer had paid and took an additional 30 cents for transaction fee. PayPal would refund the entire amount when it was a (supposed) un-authorized charge. Why is ebay charging transaction fee when paypal didnt??

Also for the first card sold, I HAD ALREADY MAILED THE CARD and so i disputed and not only did EBay charge me the above they also slapped me with a $20 dispute fee, even though their rep told me i had done everything correctly and that sometimes the buyer's bank would eat the charge.  

then i need to know how unauthorized users are accessing the ebay site. is it legit? does ebay not check ip addresses or have ML in place to detect possible fraud??