i was given the visa and its on my passport, but then i received a letter telling me i have a 5 year ban to enter canada, but my visa is still intact on my passport, if i travel and at the airport request asylum/claim refugee will i be accepted to enter canada or will be deported?
The misrepresentation clause applies to all immigration routes to Canada whether temporary, permanent or even humanitarian as defined in part 1 of the IRPA but not to asylum and refugee protection which is dealt with separately in part 2 of the IRPA. In addition, admissibility findings for asylum applicants are only decided by the IRB not the IRCC or the CBSA.
Having said that there is no way to make an asylum claim without first being in Canada so there is a practical interplay for the inadmissibility clauses in part 1 that should prevent you from arriving to Canada normally but alas don't affect your eligibility to make asylum case should you happen to be in Canada for any reason. The exception of course is for people with serious criminal convictions, human rights violations, war crimes..etc as found in part 2 of the IRPA which is in line with refugee convention/protocol agreed upon internationally.
Most airlines will electronically verify your visa at the check-in counter when you request your boarding pass, but some others may not have this capability and will only do a visual check on your passport. This is a policy followed by the airlines as mandated by Canada and has nothing to do with which country you are flying from. There has been a case filed in the Canadian Federal court somewhat similar to you in which the applicant who was denied entry claimed she did not receive the cancellation notice before she went to travel and ultimately her application was allowed.
If you do manage to arrive to Canada either by air or by any other means such as illegal crossing and you ask to make an asylum claim your case will be heard at the POE and you may be allowed to physically enter Canada but not be legally admitted meaning you won't have your passport stamped but rather confiscated along with your other documents and you will not have an immigration status but rather a suspended state of your border inspection process pending the review of the IRB to your refugee claim in which they will either declare you a convention refugee or dismiss your claim sending you back to CBSA to conclude your entry inspection most likely resulting in your deportation.
In your asylum case the misrepresentation may be used against you as the minister would like to show any negative aspects about your credibility but will not likely carry any weight in the view of the judge because this is irrelevant to your case and if that was the case then almost all asylum cases could be denied this way as almost all applicants have stated a different reason for their visit to Canada whether in their visa applications or during inspection at POE before actually making their asylum claim. Others have crossed illegally or were smuggled (committed a crime upon entry) or used fraudulent/stolen documents to reach Canada and were allowed to have a hearing. In the end it depends on you being able to demonstrate well-founded fear and the evidence you bring to the table, not how you made into Canada.
However should you be successful and declared a convention refugee the misrepresentation will still affect you as IRCC will continue to deny any visa application such as PR for 5 years and also any H&C application will be refused should you lose your asylum case for the same reason.