The first thing you need to understand (if you haven't already discovered it on match) is that none of your letters will be read unless the recipient is a FULLY PAID member. Even though you have paid to be a member you are still not able to contact the other person. There is a option available to you but it's pretty much extortion on the part of Match. You can pay an additional monthly fee where all of your mail is delivered and they can read and reply back to you.
Apart from that I can't really give you any other answers other than don't renew with this site.

That's because they are fake profiles. Don't spend any more money with this company. It's just a scam.

I cannot add much more then waht has already been said. I cannot remember ever a time when I got a reply from anyone I emailed. I did get responses form a few people who were not even close to matches for me that I remember. This site may work for some people but I do not think it works well for the majority. I have also tried Our Time which is affiliated with Match I think and I had a simialr experience through 6 months of membership. I will never subscribe to either again. I have tired OK Cupid which seems to be a bit better especially from what is free and Plentyoffish which again has a bit more free things, but to date no luck with matching me to someone I am attracted to.

Yes this is one of the dissatisfaction's I have with the site. Why post pictures and profiles is non members? It's a teaser to either get that person to pay or to get more money out if the paid member making it virtually impossible to know if you are even connecting with anyone.

Josh is correct as anyone can set up a profile and view any other public profile for free but email receiving is only part of the paid service.
Also Match have a policy of retaining profiles of people who have long lost interest in the site. I have proof of this as one of the first people presented to me was someone I dated 4 years before when I was a Match member, no romance, but we stayed friends. When I told him he said he hadn't logged on for at least 2 or 3 years.
I cannot recommend this site either. It was not a satisfactory experience for me particularly last year's membership (and I was fleeced by them so it cost me double) excect meeting my friend above when I joined 4 years ago.

Keep sending emails then try emailing the responder