I receive a lot of payments from different nationalities that all arrive in to my PayPal in my local currency, I've just had a browse thru activity etc. and it doesn't show the amount sent in that different currency.
The only time I've seen something similar is when, as an example, I buy something on eBay in AUD and I pay with PHP then it tells me the exchange rate I've copped.
You won't have been charged a fee, the fee is paid by the sender unless the payment is to a nominated friend or family member and the money comes from a PayPal balance when no fee is payable by either party.
But PayPal have their buy-at rates and their sell-at rates which they aren't particularly generous regarding so I guess that you have received a few cents/pence per unit less than you were hoping for and PayPal's exchange rates would account for that.