the difference between ' would, could' and 'will ,can'
would , could , using them to show polite in the following sentences?
The circumstance is one consumer bought a broken washing machine and complained to the factory.
The consumer writes: Please change a new one for me which will not entangle the clothes. Otherwise, I would ask you to give my money back or, I would complain to you the consumer's association.
using the " would " is to show polite ?
Thank you :)