His argument sounds reasonable. Why believe that our senses give us information about the real world? Using Xier0's argument, as it is the immediate reply, that "Science is provable & repeatable", is actually a circular response to this question. It's like saying I believe our senses give us information about the world because the information they give us about the world is consistent (insert provable and repeatable), and it is consistent, provable, repeatable, because our senses... are valid. It's a circular argument.
So I entirely sympathise why people are seduced by the argument that are senses are not reliable. The proper way I would contest to get around this is to simply recognize that the you cannot deny your senses while using your senses to do the very denying! Your senses clearly allow you to read my argument, know that it was presented by me, etc, and you realize that you are not reading a spanish argument about brain tumours because you automatically accept the validity of your senses, that they can tell you valid information about reality, specifically, the content of this forum post.
Everyone who attempts to criticise the validity of their senses always performatively contradicts themselves, if not from the very moment they present the argument, immediately after when they look left and right as they cross the street. Note however, that this does not mean your senses are ALWAYS CORRECT, it just means that they are a good way to gain information about reality; reality exists independent of you, and even if your senses you contest are slightly faulty, considering you're still alive, you haven't fallen into any holes, walked into any fires, or drowned in any lakes, all courtesy of your senses being able to give you information about the perils of reality.
See how this differs from faith. Religion is based off faith, or for some people, erroneous beliefs, but it is not a contradiction to say that faith is not a good way to gain information about reality. The next step is to say here look at the empirical evidence derived from sensory information, however if someone is committed to saying that their senses are not a valid means of gaining such information, you cannot win. Just point out that they are performatively contradicting themselves with every action they take.