Printing coming off bottle

So my wife bought a bottle. We used nuk for our previous 3 children so this is the first time buying this product. She then bought another bottle but noticed that the first bottles printing is coming off. We don't mind but the printing of the measurements is coming off. We can not give our baby the wrong measurement for formula and we can not go buy a nuk bottle because our baby is use to the teet of the nuk bottle. Also what do we do with the second bottle we bought. She sent a email to customer service and even attached a picture of the bottle and the new one we bought. The person then says that we must not worry the printing will not harm the baby so she is aware that the printing comes off. We don't use and never used sterilizers or scrub the outside of the bottle they sent her a form she filled it in and then threw the bottle away but they now saying they can nit help her because the numbers she filled in on the form is wrong and she don't have a receipt. They just stop responding.