在國外買的手機殼出了一些問題，想要寫信投訴到外國的總公司，麻煩幫我翻譯英文：去年聖誕節時在台灣的書局買了你們的手機殼，一支黑色的殼，一支白色的殼，用不到三個月音量鍵的紅色鈕部分都相繼出了問題，無法正常使用！我覺得花了那麼多錢卻買不到品質，真的很不開心！?

last year I bought your cellphone shell at the bookstore in Taiwan; one is black and the other is white. After used 3 months, both of them are malfunctional and the red volume button is not functioning at all. I am deeply not satisfied with the quality of these products. Is there any possible to solve this problem ? I am looking forward to your response.

Last Christmas, I bought your products - mobile phone shells (a white and a black), from a books store in Taiwan. Just within 3 months, the red buttons (volume) of both shells are malfunctional! I did feel frustrated to buy such inferior products at high cost.

Last year at Christmas in Taiwan's bookstore to buy your phone shell, a black shell, a white shell, with less than three months of the volume button on the red button are out of the problem, can not be used normally! I think it took so much money but can not buy the quality, really unhappy!?

I bought your mobile phone cases at a bookstore on Christmas Day last year, which included a black one and a white one. Now, I’m deeply dissatisfied with it, because in less than three months, each red bottom which controls the volume of the mobile phones was out of function. I feel that it is not worth the huge money I paid for it.