Protesters gathered outside a bank branch to oppose the cutting of opening hours of NatWest in Powys.
The changes to the branches in Montgomery, Llanidloes and Llanfair Caereinion came into effect on Monday.
Residents who have collected thousands of names for a petition objecting to the move protested outside the Llanfair Caereinion branch.
NatWest said the changes were a response to falling customer demand.
Roger Eagles, who lives in Llanfair Caereinion and took part in the protest, said: "I think it's dreadful.
"I'm really, really angry for myself and for my community as well.
"We're a wonderful community here and they will take the heart out and there will be nothing here. We need to keep the banks open. We're fighting for everything.
"This is just the start. I'm sure they think it's the start of cuts they're going to do - this is the start of us protesting and keeping the town alive."
The new opening hours are 1000-1400 in Llanfair Caereinion on a Tuesday and Friday; 1000-1400 in Llanidloes on a Monday and Thursday; and 1000-1400 in Montgomery on a Wednesday.
Montgomeryshire AM Mick Bates said several NatWest customers had turned up at the Llanfair Caereinion branch during the protest not realising it was now closed on Mondays.
"I think what annoyed me at first was the way they [NatWest] went about it. They stuck a notice up in the bank - that was the first I knew about it," he said.
Mr Bates said a copy of the bank's charter was on the door of the bank which included "making banking easy", "helping when you need us", "supporting the communities we work in" and "listening" to customers.
"They've not listened to us. We've met them and they've ignored us," he said.
A NatWest spokesperson said: "Our sub-branches at Llanidloes, Llanfair Caereinion and Montgomery have all seen a sustained fall in customer demand but, rather than close these branches, we are keen to maintain a presence in all three towns.
"The difficult decision to reduce the hours in these branches has not been taken lightly and we welcomed the opportunity recently to meet with local interested parties to explain the basis for those decisions.
"In addition to the branch service, we offer a full Welsh language telephone banking service between 9am and 5pm and are looking to expand this service later in the year."