In case it helps, Informing your bank first, then using visa credit card is good to minimize loss in event of robbery but only in places like hotels, department store, la sirena and all the super mercados like olé and jumbo
Best to change the pounds into dollars or euros at home and bring them with you. The exchange rate is about 10 pesos below what it should be. BanReservas was changing pounds at RD$48 - almost the same as the current dollar-peso exchange rate. I know the pound had lost value but it is not yet at 1-1 with the US dollar!
I have a UK bank account and have stopped using the debit card in the DR - it gets blocked every time - you have to spend ages on the phone to them getting it unblocked only for it to be blocked almost immediately again. My UK credit card is usually OK - only two cases of fraud in almost 20 years - but again the exchange rate is not favourable. Hopefully not as bad as RD$48 to the pound but it's been a while since I've used mine here so I don't know for sure.
Gotten to the point that if we do not tell the bank we are off to the DR for a few weeks they just block our US cards automatically after the first use. Plus its hard to unblock them from the DR. Tad bit of fraud lately, eh.
I am getting RD$55-58 on my HSBC debit card - but each RD$10,000 withdrawal costs 8 pounds. I have no problems using it for withdrawals apart from at Banco Popular where it doesn't work inside or outside the bank. The bank know I live here so it doesn't get blocked that often unless I make multiple withdrawals, so if you want to use it to withdraw cash then do let them know in advance as people have said. The credit card was defrauded so many times I stopped using it.