As of January 1, 2013, Canadian residents, age 18 and older, can contribute up to $5,500 annually to a TFSA. This is an increase from the annual contribution limit of $5,000 for 2009 through 2012 and reflects indexation to inflation. In other words, as of 2014, we have an accumulated limit of $31,000 of initial contribution room. Unused TFSA contribution room is carried forward and accumulates in future years. You cannot exceed this amount without penalty. So given your situation you will have to sell off what is already in your account and role the funds into buying more POET. Remember as well, if you withdraw funds (moving your mutual funds out) re-contributing to the TFSA in the same year may result in an over-contribution amount which would be subject to a penalty tax.
