According to what I have understood from your question,
you can not test subscription from the test account. Google play doesn't provide subscription testing using dummy product. you have to test on the real product.
Now question arises how can I test subscription
you can check subscription by purchasing real product and check product status or purchase cancellation using the purchase status api from your server.
you can also get more information from the given link below for the step by step cancellation purchase status:
1) link1
2) link2
you can simply query every day and check your subscription is valid or not and also get it's expiration date.
I also have one other option with out pay for any charges on your real product, you can set trial period in the Google console and before trial period ends up cancel subscription from the Google play store Menu -> MyApp -> Subsciption and cancel product and check above procedure given in the links.
EDIT:
Important: In all cases, you must continue to offer the content that
your subscribers have purchased through their subscriptions, for as
long any users are able to access it. That is, you must not remove any
subscriber’s content while any user still has an active subscription
to it, even if that subscription will terminate at the end of the
current billing cycle. Removing content that a subscriber is entitled
to access will result in penalties. Please see the policies document
for more information.
more information check below links:
1)
http://developer.android.com/google/play/billing/billing_subscriptions.html#cancellation
2) https://support.google.com/googleplay/answer/2476088?hl=en
3)
https://support.google.com/googleplay/android-developer/answer/140504?hl=en
You can not done this with out waiting until the subscription process cycle completes after cancellation of subs product, the only way remaining which is Free trial
version it's only the way to provide us to test for the product cancellation in which product cancel immediately after you cancel subscription trial period, it will not continue until even trial periods ends.
more information check below link:
http://developer.android.com/google/play/billing/billing_subscriptions.html#administering
And I think it is better way because in the trial period you should go
with the actual credit card payment process but you doesn't need to
pay anything for it. Google play record the transaction as $0.00 for
the subscription process. And if you cancel the subscription the you
should not pay anything for testing, but yes I am not sure free trial version
is worked before you publish the app but it is only get by efforts only.
Conclusion:
In the current api it is not possible to test subcription product like
normal products and if user has been cancel the subscription product
then you have to wait to purchase the same product until the
subscription cycle has been expired, there is no another way if the
subscription cycle is going on and you can test for the same product
again before subscription cycle ends. And if you still want to test
for the same product then you have to choose another account for
testing it or another way is Free trials, you will not be any charged
until your Free trials period expired or cancel subscription in that
period and for the testing account before publish the app you will be refunded
automatically after 14 days of purchased product according to my
knowledge.
Hope it will solve your problem.