Banks block thousands of cards

this is very interesting, i was recently in south of spain for holiday in September visiting a friend, and had no problems using my card at spanish ATMs. however, this week i went to UK to visit friends and family, Only to be told at Sixt rent a car in Heathrow that my card was refused. This was greatly unappreciated, but luckily they contacted Mastercard, and my rent a car was approved. However, i was NOT emailed or SMSed from Refiessen bank about this disruption. Not a word...this is disheartening from a bank that i thought was supposed to be informative with a german correctness.
Im yet to check my funds, but im hopeful nothing was taken by fraudsters. God Damn them! ;-)