On XX/XX/2016, while I was in XXXX, I purchased a mobile AC unit from XXXX on my Bank of America credit card in the amount of {$670.00}. A/C was delivered to my apartment the next day. After unpacking the unit & using it for a few days, we noticed it was n't cooling. We packed the AC unit along with all the parts back into the box it was delivered in & went to the store to return the defective item within the 14 day return time frame. Their return policy on the back of receipt stated customer has 14 days to return item for full refund. When we arrived at XXXX, we were told the unit was n't eligible for refund because the box had been opened. I disputed this with the manager because obviously we would have to open the box & use the unit to realize it was defective. They told me we would have to leave the unit to be examined by their repair shop before they could issue a store credit. The inspection would take 2-3 weeks & we were leaving XXXX in 2 days. I explained we did n't have time to wait for the unit to be inspected & I requested either a refund or an exchange for a similar unit that was the exact same price. They denied my request. After spending 2 hours disputing this issue in the store, we left the unit with them. They sold us a defective item, would n't exchange it or give us a refund & they still have the unit in their possession. I immediately placed a dispute on the charge with Bank of America. I received a letter from Bank of America stating they needed all supporting documentation, a detailed letter & the reason our return was not successful. We sent Bank of America everything they requested via fax/mail. On XX/XX/2016, I received a letter from Bank of America stating they were unable to obtain credit from the merchant. I called Bank of America Merchant Response Department & spoke with XXXX & XXXX. I was on the phone with them for over 2 hours explaining what happened & inquiring why the credit was denied. XXXX told me that she would re-open the dispute for further investigation. On XX/XX/2016, I received another letter from Bank of America stating that after further review, they were n't able to determine a billing error occurred. I called Bank of America again & after speaking to XXXX again, she requested I send XXXX 's return policy. I faxed her XXXX 's return policy along with the return policy on the back of my receipt. XXXX explained that because the information was in XXXX, her team was having a hard time deciphering it, but she would find someone that could translate it & she would be in touch. On XX/XX/2016, we received another letter from Bank of America stating they exercised all available options & they were unable to obtain a credit from the merchant. I called Bank of America yet again & spoke with a supervisor. XXXX, the supervisor with Bank of America, stated that since the merchant had looked at the faulty unit & deemed it was working properly & it was now ready to be picked up, they were unable to issue us a credit. I explained that we returned the item within the 14 day time grace period, I did not want this unit, it was no longer in my possession, XXXX refused a refund or an exchange. XXXX then stated that due to all of the documentation we sent being in XXXX, they could not fully decipher the merchant 's return policy & that she would have to get someone else to translate the information yet again, but that they would n't be able to respond to any further correspondence regarding this claim. I am now requesting your assistance, I have submitted everything as requested, I returned the defective unit within the allotted time frame, Bank of America has had a sufficient amount of time to translate the documents, I am within my rights, I 've spent numerous hours disputing this & I should not have to pay for this item. Bank of America wo n't help.