GBS Solar Selling 2nd hand/ faulty solar equipment

bought so called new 150AH deep cycle gel battery for solar unit from them, noticed when I connected the battery that it has been used before(connection leads markings burned in by the sun and scratched all round, when I returned the battery they could not supply a replacement unit but was also unwilling to refund my money. When you phone the owner- Peter he doesn't answer his phone. They tell you that there is a 2 year Guarantee but this is not written on their hand written invoices but in any case means nothing as they are not willing to help in any way after they have taken your money, by the way they only take cash.